Has anyone used the PS Audio Ultimate Outlet?

Can the human ear detect a difference? Is this a waste of $299? Views appreciated.
I haven't but was considering one for my LINN gear. Apparently LINN say don't go there.
I use several and like what they do. To me, they increase the sense of black/emptiness around the notes being played. I've observed this with both tube and ss systems and with my headphone system. I think they're worth a try since PS Audio provides a 30 day satisfaction guarantee. -- You might want to check previous threads. There were quite a few negative comments as I remember.
They say it just doesn't sound good [ie tuneful]. They also recommend using their power cords.
UO is really a great device but the result may not be hear right after you put it in your system ( I took about a month to me to hear what wonder it can do, more detailed background, remove any kind of hiss/humm your system may had because of a poluted AC line, and more lifelike music.)
I use them for power amps. Agree with what Danner says and also I feel there is an improvement to the flow of music. The lab cables are good too. I use it for the CD transport. I was actually quite surprised that the lab cable sounds much better than the mini labs on the transport. I have also tried the ultimate outlet on the Linn with Naim power supply, it didn't do much.
After direct comparison I can say that the high current
ultimate outlet is great for your amplifier(s). I did not notice much difference using it on my source equipment and compared to the P300 everything was compressed. But the high current helped my amp really open up to a new level.
It works great with Atmasphere OTL amplifiers - increases the dynamics, reduces the noise and harshness which results in a very musical presentation.